The United States Environmental Protection Agency warns that indoor sources of pollution such as building materials, household cleaning products, oil, gas, wood and kerosene release harmful gases or particles into the air. Inadequate ventilation and high humidity increases the concentrations of these pollutants.
Gases
The Centers for Disease Control and Prevention identifies common gases that contaminate the air inside homes, including carbon monoxide, radon and ozone. Carbon monoxide is an odorless, colorless gas that is difficult to detect. Appliances such as wood stoves, gas-fueled ranges, space heaters and furnaces emit carbon monoxide into the air. Symptoms of carbon monoxide poisoning include nausea, chest pain, headache and confusion, and can lead to loss of consciousness or death, according to the CDC. Radon is a radioactive, odorless, colorless gas that occurs in soil and rock as uranium decays and enters the home through cracks and the water supply. According to the CDC, radon is a radioactive element that causes lung cancer. Ozone is a reactive, unstable gas that adversely affects human health. It occurs naturally in Earth's atmosphere and seeps into homes. The CDC warns that inhaling ozone damages the lungs and leads to respiratory problems.
Biological Contaminants
Biological pollutants come from living organisms. Common biological contaminants include mold, pet dander, mites, dust, pollen, fungi, viruses, bacteria and mildew. These substances occur in every home and are impossible to completely eliminate. The University of California at Davis warns that exposure to biological pollutants leads to allergic reactions in some people. People can reduce concentrations of biological contaminants by controlling moisture levels inside their homes, removing water-damaged materials and reducing humidity levels by installing exhaust fans in bathrooms and kitchens, according to Environmental Health Watch, an Ohio environmental group.
Asbestos
The construction industry commonly used asbestos, a type of mineral fiber, in building materials such as roofing, siding, insulation and floor tiles, prior to the 1950s. However, as the adverse health effects of these materials became known, the use of asbestos was banned in the late 1970s. Exposure to asbestos increases the risk of lung cancer and mesothelioma, according to Environmental Health Watch.
Lead
Lead is a metal that melts into thin sheets that can be shaped easily. It is also resistant to extreme weather. These properties make lead a useful material for building components, such as pipes. Lead is released into the air by scraping or sanding lead-based paint and using lead for indoor activities, such as stained-glass making or soldering, according to the EPA. The CDC warns that lead is a toxic substance that has adverse effects on all systems of the human body.
Volatile Organic Compounds
Household chemicals, such as cleaning supplies, paint, or varnish, contain organic compounds that vaporize and become gases, which are called volatile organic compounds. The EPA warns that these chemicals cause short- and long-term health problems such as throat irritation, headaches, nausea and damage to the liver and central nervous system. People can reduce exposure to these chemicals by following instructions for using household products and increasing ventilation when using products containing VOCs, according to the EPA.
References
- U.S. EPA: An Introduction to Indoor Air Quality
- Centers for Disease Control and Prevention: Healthy Housing Reference Manual: Chapter 5: Indoor Air Pollutants and Toxic Materials
- UC Davis Extension Toxicology Network: Indoor Biological Pollutants
- Environmental Health Watch: Residential Pollution Hazards: When Is Your Home Not a Haven?
- U.S. EPA: Indoor Air Quality: Volatile Organic Compounds
